Organic compounds -- part of the class 532-570 series – Organic compounds – Carbohydrates or derivatives
Reexamination Certificate
1999-08-30
2001-07-17
Priebe, Scott D. (Department: 1632)
Organic compounds -- part of the class 532-570 series
Organic compounds
Carbohydrates or derivatives
C536S023100, C536S024310, C435S006120
Reexamination Certificate
active
06262247
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to nucleic acid molecules comprising at least fragments of human genes homologous to rat genes expressed in response to treatment with the polycyclic aromatic hydrocarbon benzo(a)pyrene. The invention also relates to the use of these molecules in diagnosis, prognosis, prevention, and treatment of human disorders such as cancer and its complications. The invention further relates to the use of these molecules in rat model systems for evaluation of therapies for disorders such as cancer and its complications.
BACKGROUND OF THE INVENTION
Phylogenetic relationships among organisms have been demonstrated many times, and studies from a diversity of prokaryotic and eukaryotic organisms suggest a more or less gradual evolution of biochemical and physiological mechanisms and metabolic pathways. Despite different evolutionary pressures, proteins that regulate the cell cycle in yeast, nematode, fly, rat, and man have common chemical or structural features and modulate the same general cellular activity. Comparisons of human gene sequences with those from other organisms where the structure and/or function may be known allow researchers to draw analogies and to develop model systems for testing hypotheses. These model systems are of great importance in developing and testing diagnostic and therapeutic agents for human conditions, diseases and disorders.
Polycyclic aromatic hydrocarbons (PAH), such as benzo(a)pyrene (BP), are ubiquitous environmental pollutants known to cause cancer in laboratory animals. PAH induce tumors in various tissues of animal species regardless of the route of administration. Human exposure to PAH in food, air, and water is increasing, and epidemiological studies show a higher incidence of lung, skin, and bladder cancer in individuals exposed to high levels of PAH, e.g. cigarette smokers and coke oven workers.
PAH are lipophilic compounds oxidatively metabolized to epoxides, quinones, and phenols by the body's cytochrome P-450-dependent monooxygenase and epoxide hydrase. These metabolites are conjugated to more hydrophilic metabolites, most of which are secreted. However, some of the metabolites are capable of binding extensively and covalently to cellular macromolecules, such as DNA. Formation of PAH-DNA adducts appears to be an essential first step in PAH-induced neoplasia. If the cell cannot repair the damaged DNA before synthesis occurs, then replication on the damaged template can result in mutation. The two most common reactive metabolites of BP which bind to DNA are diol epoxide derivatives formed by the sequential action of the cytochrome P-450-dependent monooxygenase system and epoxide hydrase. Other PAH, such as benzanthracene, chrysene, 3-methylcholanthrene, and dimethylbenzanthracene, are also converted to very reactive diol epoxides that bind to DNA in vivo. All of these diol epoxides have a similar structure involving an epoxide ring in the bay region and have been called “bay region diol-epoxides” (Stowers and Anderson (1985) Environ. Health Perspect. 62:31-39).
The major DNA adduct formed by BP metabolites is(+)-7&bgr;, 8&agr;-dihydroxy-9&agr;,10 &agr;-epoxy-7,8,9,10-tetrahydrobenzo(a)pyrene (BPDEI) bound to the N2 of guanine residues. Similar adduct patterns are seen in each tissue examined in mice and rabbits regardless of dose, route of administration, or time of sacrifice after dose. Differences in tissue susceptibility to PAH-induced neoplasia between different tissues may be due to the method of adduct repair. The liver, which is relatively resistant to carcinogenesis by BP, removes DNA adducts by excision repair. Lung, skin, and brain, which are more susceptible to BP-induced carcinogenesis, have little excision repair and remove DNA adducts primarily by cell turnover. If turnover rates in tissues are slow, significant levels of PAH metabolite-DNA adduct can accumulate, especially if there is continuous long-term exposure to PAH. The persistence and accumulation of DNA adducts could inhibit replication and transcription and lead to mutagenesis and carcinogenesis (Stowers and Anderson, supra).
There is growing evidence that predisposition to cancer may reside in polymorphic genes involved in carcinogen metabolism and repair. One major goal of epidemiologists is the identification of individuals who are exposed to high levels of carcinogen, carry cancer-predisposing genes, and lack protective factors. A combination of cancer-predisposing genes could be used as an intermediate risk marker rather than taking diagnosis of cancer as the endpoint. Such markers may include PAH-DNA adduct level and polymorphism in PAH-metabolizing enzymes such as the cytochrome P450 family member CYP1A1, the 4 S PAH-binding protein glutathione S-transferase (GSTM1), and cAMP-dependent protein kinase (Bhat et al. (1996) J. Biol. Chem. 271:32551-32556; and Bartsch, H. et al. (1998) Recent Results Cancer Res. 154:86-96). For example, Bartsch et al. (supra) showed that BPDE-DNA adduct levels in bronchial tissues of cigarette smokers with high CYP1A1 inducibility and inactive GSTM1 were approximately 100-fold higher than in smokers with an active GSTM 1.
Identification of genes that are expressed in response to polycyclic aromatic hydrocarbon exposure provides new diagnostic and therapeutic targets. The present invention satisfies a need in the art by providing new compositions that are useful for diagnosis, prognosis, treatment, prevention, and evaluation of therapies for cancer and its complications.
SUMMARY OF THE INVENTION
The invention provides for a substantially purified nucleic acid molecule comprising a gene that is expressed in response to polycyclic aromatic hydrocarbons (PAH). In one aspect, the nucleic acid molecule comprises a sequence selected from (a) a nucleic acid molecule which encodes the protein of SEQ ID NOs:6-8 or a portion thereof; (b) a nucleic acid molecule of SEQ ID NOs:1-5 or a fragment thereof; (c) a nucleic acid molecule complementary to the nucleic acid molecule of (a) or (b); (d) a probe which hybridizes to the nucleic acid molecule of (a), (b), or (c). In another aspect, the nucleic acid molecule comprises a sequence selected from (a) a nucleic acid molecule which encodes the protein of SEQ ID NO:14 or a portion thereof; (b) a nucleic acid molecule of SEQ ID NOS:9-13 or a fragment thereof; (c) a nucleic acid molecule complementary to the nucleic acid molecule of (a) or (b); (d) a probe which hybridizes to the nucleic acid molecule of (a), (b), or (c). The invention further provides an expression vector comprising any of the above described nucleic acid molecules and host cells comprising the expression vector. The invention still further provides a method for treating or preventing a disease or condition associated with the altered expression of a gene that is expressed in response to PAH comprising administering to a subject in need a nucleic acid molecule described above in an amount effective for treating or preventing the disease. The invention also provides a pharmaceutical composition comprising a nucleic acid molecule and a pharmaceutical carrier.
The invention additionally provides methods for using a nucleic acid molecule. One method uses the nucleic acid molecule to screen a library of molecules or compounds to identify at least one ligand which specifically binds the nucleic acid molecule and comprises combining the nucleic acid molecule with a library of molecules or compounds under conditions to allow specific binding and detecting specific binding, thereby identifying a ligand which specifically binds the nucleic acid molecule. In this first method, the library is selected from DNA molecules, RNA molecules, PNAs, mimetics, and proteins; and the ligand identified using the method may be used to modulate the activity of the nucleic acid molecule. A second method uses the nucleic acid molecule to purify a ligand which specifically binds the nucleic acid molecule and comprises combining the nucleic acid molecule with a sample under conditions to allow specific bindin
Azimzai Yalda
Kaser Matthew R.
Yue Henry
Brunovskis Peter
Incyte Genomics Inc.
Incyte Genomics, Inc.
Priebe Scott D.
LandOfFree
Polycyclic aromatic hydrocarbon induced molecules does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Polycyclic aromatic hydrocarbon induced molecules, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polycyclic aromatic hydrocarbon induced molecules will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2492525